Portion of an audio mixer



FIG. 1 is a perspective view of a portion of an audio mixer showing our new design;

FIG. 2 is a close-up perspective view of the claimed portion shown in FIG. 1;

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a front elevational view thereof.

The broken line showings of the surrounding areas of the mixer in FIGS. 2–4; the remainder of the mixer in FIG. 1; the indicia on the rectangular areas of the vertical panel; and the controls on both the horizontal and vertical panels are for illustrative purposes only and form no part of the claimed design. The heavy broken line delineating the shaded areas from the unshaded areas denotes the boundary of the claimed design, and does not itself form any part of the claimed design. 

The ornamental design for a portion of an audio mixer, as shown and described. 